Table 2 From 15 major themes from the expertise approach and 9 major themes from clustering approach, to the 9 major challenges

E1 Interface between sea and any building on shore

C1 Human health and sea

1 Understanding marine ecosystems evolutions (E10, C2, C3)

E2 Tourism, onshore and offshore

C2 Dynamics of marine ecosystems

2 Securing food and therapeutics supply from sea (E11, E12, E13, S1)

E3 Bio-remediation

C3 Impacts of any infrastructure at sea on marine ecosystems

3 Mastering the colonization of sea (E1, E6, E7, E8, E10, C3, C5)

E4 Offshore technologies for fisheries and aquaculture

C4 Risks related to the sea

4 Developing technologies for the exploitation of sea resources (E4, E5, E6, E7, C6, C8)

E5 Remote operated exploitation of minerals

C5 Management of the multiple uses of marine areas and resources

5 Preventing risks and hazards (E9, C4)

E6 Impact assessment of deep sea exploitation

C6 Development of marine technologies

6 Developing biotechnologies for industrial, sanitary or remedial uses (E3, C1, C6, C8)

E7 Synergies between marine renewable energies and living resources exploitation

C7 Security in high sea

7 Developing education, sustainable tourism and responsible social practices (E2, E14)

E8 Integrated global coastal zone management

C8 Processing and transformation of all marine resources and their impacts including bioremediation

8 Building an adapted international law of the sea (E9, E12, E13, E15, C7, C9)

E9 Safety at sea

C9 Governance; rules and regulations

9 Systematizing and globalizing monitoring and control of activities at sea (E8, C3, C5, C7, C9)

E10 Ecosystemic services: knowledge and uses

E11 Contribution of seafood to world scale food security

E12 International rules for sea resources management and trade

E13 Property rules of living resources, notably on straddling stocks

E14 Value adding for culture and game

E15 Property rules and share of benefits for high sea resources